• Background Sensitivity: reduction in dimensions of cerebral hemispheres is observed by postnatal day 4, however, on the mixed background the substantial reductions reported in the C57BL/6J forebrain are not observed

• at E12.5, telencephalon remains single chambered and clear distinction between cortical plate and ganglionic eminences is absent

• in E11.5 mutants, neural progenitors and postmitotic neurons are intermingled throughout NE but in wild-type brain, progenitors are mainly confined to ventricular surface of forebrain and postmitotic neurons are found along apical-basal NE axis

• at E18.5, the distance between the lateral edge of the IHC and the medial edge of the first row OHC (a measure of the degree of PC development) is significantly decreased along the length of the cochlea

• at E18.5, PCs with weak or no lumenal projections are noted along the entire cochlear length with no region-specific variations

• at E18.5, the distance between the lateral edge of the IHC and the medial edge of the first row OHC (a measure of the degree of PC development) is significantly decreased along the length of the cochlea

• at E18.5, PCs with weak or no lumenal projections are noted along the entire cochlear length with no region-specific variations

• thalamthalamocortical projections are similar to controls at P0, but by P3, axonal bundles projecting from the thalamus through the cortical white matter are reducedcortical projections are similar to controls at P0, but by P3, thalamocortical projection is reduced

• reduction in the number of lateral geniculate nucleus projections to the visual cortex and anteroventral and laterodorsal nuclei projections to retrosplenial cortex

• at E18.5, fewer BrdU+ cells are found within the upper cortical layers of the subventricular zone while more are detected in the superficial positions in the cortical plate compared to in wild-type mice

• at E18.5, fewer BrdU+ cells are found within the upper cortical layers of the subventricular zone while more are detected in the superficial positions in the cortical plate compared to in wild-type mice

• phenotype is stated to be comparable to that of mice that are compound heterozygous for Fgfr1tm1.1Upir and Fgfr1tm1Upir and also heterozygous for Foxg1tm1(cre)Skm; however, no data are presented in J:78879

• at birth, the sensory epithelium of the upper cochlear half is arranged in small sensory patches that mainly consist of IHCs and pillar supporting cells, while the lower cochlear half is less severely affected

• at E16.5, mutants display no molecular signs of HC specification or differentiation in the gap regions found between sensory patches; OHCs are more severely affected

• at E16.5, the remaining HCs in the sensory patches appear to undergo normal differentiation

• at E18.5, most cochlear sections are devoid of HCs and the greater epithelial ridge is abnormally thin, due to reduced precursor cell proliferation in the ventral wall of the cochlear duct between E12 and E15.5

• apparently, the remaining precursors of the organ of Corti preferentially differentiate into IHCs and pillar cells

• no differences in precursor cell proliferation rate are observed in the dorsal, non-sensory wall of the cochlear duct

• at E16.5, mutants display no molecular signs of HC specification or differentiation in the gap regions found between sensory patches; OHCs are more severely affected

• at E16.5, the remaining HCs in the sensory patches appear to undergo normal differentiation

• at E18.5, most cochlear sections are devoid of HCs and the greater epithelial ridge is abnormally thin, due to reduced precursor cell proliferation in the ventral wall of the cochlear duct between E12 and E15.5

• apparently, the remaining precursors of the organ of Corti preferentially differentiate into IHCs and pillar cells

• no differences in precursor cell proliferation rate are observed in the dorsal, non-sensory wall of the cochlear duct

• at E17.5, the middle part of the cochlea has two disorganized rows of hair cells instead of the normal stereotyped pattern of 3 rows of outer hair cells and 1 row of inner hair cells: towards base of the cochlea, the number of hair cells is severely reduced and instead of a continuous band of two rows, the rows are broken up and irregular islands of hair cells are present

• in mutants, the number of hair cells per 100 microns of cochlea length is reduced to 25.8 as compared to 63.5 in wild-type controls

• at E17.5, the middle part of the cochlea has two disorganized rows of hair cells instead of the normal stereotyped pattern of 3 rows of outer hair cells and 1 row of inner hair cells: towards base of the cochlea, the number of hair cells is severely reduced and instead of a continuous band of two rows, the rows are broken up and irregular islands of hair cells are present

• in mutants, the number of hair cells per 100 microns of cochlea length is reduced to 25.8 as compared to 63.5 in wild-type controls